Two-piece head restraint and method for making same

ABSTRACT

A head restraint comprising a first core portion including an exterior surface, an interior and a perimeter edge between the exterior surface and the interior, a first outer layer provided about at least a region of said exterior surface of said first core portion, a second core portion including an exterior surface, an interior and a perimeter edge between the exterior surface and the interior, and a second outer layer provided about at least a region of said exterior surface of said second core portion, wherein at least a region of the perimeter edge of the first core portion is attached to at least a region of the perimeter edge of the second core portion to define a perimeter seam therebetween.

RELATED APPLICATIONS

The present application claims the benefit of international patentapplication serial number PCT/US2005/018362 filed on May 25, 2005, whichclaims the benefit of U.S. Provisional Patent Application Ser. No.60/575,555 filed on May 28, 2004 the contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is generally related to a head restraint, and inparticular to an open style head restraint with a closeout for bothaesthetic and/or structural purposes, and a method for making same.

2. Description of the Related Art

Recent legislation has required vehicle seat head restraints to extendhigher in vehicles for improved safety. For example, Europeanlegislation requires that the top of the head restraint be positioned750 mm above the hip pivot point, which is substantially higher thanmost current designs. As a result of these tall seat designs, either theseat back is made taller and/or the head restraint is made taller.Because a taller seat back may obstruct the view of the occupant, it ispreferred that the head restraint is made taller and includes a halo oropening to maximize visibility.

With a taller or larger head restraint design made of a foam fillermaterial, the overall weight of the head restraint increases, therebyreducing fuel economy of the vehicle. In addition, a taller or largerhead restraint design imposes design constraints, such as a stitch seamfor the covering material.

The inventors of the present invention has recognized these and otherproblems associated with conventional head restraint designs and havedeveloped a two-piece head restraint design that reduces the overallweight of the head restraint, while improving visibility, impactproperties, and increasing the modularity of the design.

SUMMARY OF THE INVENTION

A head restraint comprising a first core portion including an exteriorsurface, an interior and a perimeter edge between the exterior surfaceand the interior, a first outer layer provided about at least a regionof said exterior surface of said first core portion, a second coreportion including an exterior surface, an interior and a perimeter edgebetween the exterior surface and the interior, and a second outer layerprovided about at least a region of said exterior surface of said secondcore portion, wherein at least a region of the perimeter edge of thefirst core portion is attached to at least a region of the perimeteredge of the second core portion to define a perimeter seam therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is a side perspective view of an assembled two-piece headrestraint according to an embodiment of the invention;

FIG. 2 is an exploded view of the two-piece head restraint of FIG. 1;

FIG. 3 is a front elevational view of the armature, the cross member,and the closeout of FIG. 2 with the non-permeable material and attachingmeans for keeping the non-permeable material in place during themanufacturing process;

FIG. 4 is a perspective view of applying a mold-release coat to one ofthe mold surfaces while the mold assembly is in an open position;

FIG. 5 is a front elevational view of the completed halo style headrestraint when removed from the mold assembly; and

FIG. 6 is a front elevational view of a completed open style headrestraint according to an alternate embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 and 2, a head restraint 10 is shown accordingto an embodiment of the invention. The head restraint 10 comprises afirst portion, shown generally at 12, and a second portion, showngenerally at 14 that are pre-formed prior to being attached to eachother. One or both of the first and second portions 12, 14 may include acover material 16 for providing an aesthetically pleasing appearance(Class “A” surface) to the head restraint 10. Alternatively, the covermaterial 16 can be omitted and the outer surfaces of the first and/orsecond portions 12, 14 may provide an aesthetically pleasing appearance(Class “A” surface) by using spray skin process.

One aspect of the invention is that one or both of the first and secondportions 12, 14 is made of core material 18 having energy absorbingproperties while providing a dimensionally stable surface. For example,the core material 18 may comprise an expanded polypropylene (EPP) foammaterial, or the like. The EPP foam material is lighter in weight thanconventional materials, such as a foam filler core material. Inaddition, the density of the EPP foam material is directly proportionalto the pressure at which the EPP foam material is injected into the moldtool. For example, a higher injection pressure produces a higher densityEPP foam material, as compared to a lower injection pressure. Thus, thedensity of the EPP foam material can be selected to provide improvedenergy absorbing properties, as compared to conventional foam fillermaterials. Further, the EPP foam material can have a non-uniform densitythroughout the head restraint 10 by selecting the pressure at which thecore material 18 is injected into the mold tool. For example, the corematerial 18 can have a lower density at the outer surface of the headrestraint 10, and can have a higher density at the center of the headrestraint 10, or vice versa.

As shown in FIG. 2, one or both of the first and second portions 12, 14can be formed to include a cavity 20 that is adapted for receiving andsecuring a head restraint post 22 in place. The size of the cavity 20can be such that the post 22 is press fit into the cavity 20.Alternatively, one or both of the first and second portions 12, 14 mayinclude a relatively softer material, rather than including the cavity20, for securing the post 22 in place. The relatively softer EPP foammaterial can be injected into the mold tool using a two-shot injectionmolding operation in which the first shot of injected EPP foam materialis set before injecting the second shot of material.

Once the post 22 is secured in place, the first and second portions 12,14 can be attached to each other using a variety of different means, andthe invention is not limited by the means for attaching the first andsecond portion 12, 14 to each other. For example, the first and secondportions 12, 14 can be attached using a tongue and groove arrangement 24of a type well-known in the art. The tongue and groove arrangement 24provides a means for mechanically interlocking and securely attachingthe first and second portions 12, 14 to each other. It will beappreciated that other conventional means for attaching the first andsecond portions 12, 14 to each other are within the scope of theinvention.

Once the first and second portions 12, 14 are attached to each other,the head restraint 10 forms a seam 25 between the first and secondportions 12, 14. Unlike conventional head restraints in which the seamis sewn by a separate operation, the seam 18 of the invention can beformed by using an edge wrapping technique to provide a clean, neat andprecise appearance for the head restraint 10.

Once the cover material 16 is wrapped around the edge 26, the first andsecond portions 12, 14 can be placed in a bond tool that applies heat tothe first and second portions 12, 14. While in a slightly molted state,the first and second portions 12, 14 are pressed together to bond thefirst and second portions 12, 14 together. The first and second portions12, 14 can be heated using any suitable means, such as ultrasonicwelding, or the like. Alternatively, the first and second portions 12,14 can be bonded to each other using any suitable means, such as byapplying an adhesive to the first portion 12 and/or the second portion14, the cover material 16, or any combination thereof. It will beappreciated that the invention is not limited by the means for bondingthe first and second portions 12, 14 to each other, and that theinvention can be practiced by using any suitable means, such as amechanical fastener, vacuum or bladder bonding, or the like.

After the first and second portions 12, 14 are attached together, anyexcess cover material 16 can be trimmed by transferring the heatrestraint 10 to a trim tool. The trimming of any excess cover material16 can be accomplished by various means, such as laser cutting, handtrimming, hard tool, water jetting, or the like.

After any excess cover material 16 is trimmed, the head restraint 10 canbe transferred to an assembly tool where all designed components, suchas the posts 22, are placed into the head restraint 10. As shown inFIGS. 3 a and 3 b, one or both of the first and second portions 12, 14may include one or more engineered areas 28 when in an unfolded state.An adhesive 30 is then applied within each engineered area 28 and thefirst and/or second portion 12, 14 is folded to form the final surfaceshape for the portion 12, 14.

Referring now to FIG. 4, a head restraint 40 is shown according to analternate embodiment of the invention in which the cover material 16 isused as a hinge 32 to form a “clam shell” design.

Other designs for the head restraint 10 are contemplated by theinventors and are within the scope of the invention. For example, theprinciples of the invention can be applied to a “halo” style headrestraint design, as shown in FIGS. 5 and 6. As used herein, the “halo”is defined by the central opening of the doughnut-shaped head restraint10.

For a “halo” style head restraint design as shown in FIG. 5, a headrestraint 50 of the invention may include a closeout 52 made of a meshor net material that is disposed in an opening defined by first andsecond core portions. The first and second core portions each includesecondary edges 54, 56 that define a secondary seam. However, it will beappreciated that the invention is not limited by the material used forthe closeout 52, and that the invention can be practiced by using acloseout 52 made of any desired material. For example, the closeout 52may be made of a cellular material as shown in the illustratedembodiment, such as a net, mesh, or the like. Alternatively, thecloseout 52 may be made of a non-cellular or substantially solidmaterial, such as a plastic, fiberglass, or the like. For safety, thecloseout 52 may add structural integrity to the head restraint 50 forabsorbing energy during impact. In addition, the closeout 52 may have a“see-through” property to allow the occupant to have a substantiallyunobstructed view through the halo of the head restraint 50.

Unlike conventional “halo” style head restraint designs, the “halo”style head restraint 50 of the invention does not suffer from leakageassociated with the conventional foam materials used to form the headrestraint. In the invention, the EPP foam material is cured prior toapplication of the posts 22 that are used in the invention.

However, the invention is not limited to a “halo” style head restraintdesign as shown in FIG. 5. For example, as shown in FIG. 6, theinvention can be practiced with a head restraint 60 in which an openingis formed between a pair of upright posts 62 without a top and/or bottommember connecting the posts 62 of the head restraint 60 together to forma “horse shoe” and/or a “goal post” head restraint design.

Other alternate embodiments of the invention are contemplated by theinventors and within the scope of the invention. For example, anoptional mold-release coat may be applied to each of the mold surfaces(not shown). For brevity, the mold-release coat can be to be applied toonly one mold surface. The purpose of the mold-release coat is topromote efficient removal of the head restraint 10, 50, 60 from the moldassembly (not shown) after the forming process is complete.

Then, an optional in-mold coat can be applied to the mold-release coaton each of the mold surfaces when the mold assembly is placed in theopen position. The in-mold coat is preferably applied in a generallyuniform manner to promote consistent gloss, texture, and color of theouter contour of the head restraint 10, 50, 60. Preferably, the in-moldcoat is a waterborne urethane coating, which can be applied by anair-atomized coating applicator such as a spray gun or bell applicator.Alternatively, the composition and means of applying the in-mold coatmay be of any suitable type.

Next, a skin coat is applied to the in-mold coat in a manner similar toapplication of the in-mold coat. The composition of the skin coat ispreferably a two component polyurethane elastomer including a polyolcomponent and an isocyanate component as disclosed and described in U.S.Pat. No. 5,885,662 which is incorporated herein by reference in itsentirety. The in-mold coat, which is applied to each mold half bonds tothe respective skin coat to form a structural skin. Depending on theformulation of the skin coat, the in-mold coat can be eliminated fromthe process.

Once the mold-release coat, the in-mold coat and skin coat are applied,the mold assembly is then placed in the closed position. Before the moldhalves are moved to the closed position, the coats are preferablyallowed to at least partially harden to a non-liquid or gel state. Oncethe mold halves have reached, or just prior to reaching, the closedposition, the mold halves can be mechanically clamped or locked togetherto ensure that the mold assembly is properly placed and held in theclosed position.

When in the closed position, the coats of the first mold half bond withthe coats of the second mold half at the junction between the moldhalves. That is, the portion of the coats around the perimeter of thefirst mold surface bond with the portion of the coats around theperimeter of the second mold surface. The bond between the coats of themold halves is more durable than a conventional head restraint havingsewn seams because the bonding of the subject invention is particularlyresistant to tearing, ripping, snagging and opening during repeated useover the life of the head restraint 10, 50, 60.

The EPP foam material 18 is then injected into one of the mold cavities.After being injected, the EPP foam material 18 expands in the moldcavity and bonds with the structural skin, formed by the coats to formthe head restraint 10, 50, 60. The EPP foam material 18 may bemanufactured of a color that is complementary to the color of thestructural skin, which provides the advantage of partially concealingany tears, cuts or breakage in the structural skin that may occur duringthe life of the head restraint.

The EPP foam material 18 is allowed to expand in the mold cavity andpartially cure. The EPP foam material 18 is injected into the other moldcavity and allowed to expand and partially cure. While the EPP foammaterial 18 in both mold cavities are in the partially cured condition,the posts 22 placed within the groove 20 and the mold halves are closed.When the EPP foam material 18 is cured, the mold halves are opened toremove the completed head restraint 10, 50, 60.

While the invention has been specifically described in connection withcertain specific embodiments thereof, it is to be understood that thisis by way of illustration and not of limitation, and the scope of theappended claims should be construed as broadly as the prior art willpermit.

1. A head restraint, comprising: a first core portion including anexterior surface, an interior and a perimeter edge between the exteriorsurface and the interior; a first outer layer provided about at least aregion of said exterior surface of said first core portion; a secondcore portion including an exterior surface, an interior and a perimeteredge between the exterior surface and the interior; and a second outerlayer provided about at least a region of said exterior surface of saidsecond core portion, wherein material defining at least a region of theperimeter edge of the first core portion is directly attached tomaterial defining at least a region of the perimeter edge of the secondcore portion, wherein an edge of the first outer layer is directlyattached to an edge of the second outer layer to define a perimeter seamtherebetween, wherein the first outer layer is a cover wrapped aroundthe perimeter edge of the first core portion and toward the interior ofthe first core portion, and wherein the second outer layer is a coverwrapped around the perimeter edge of the second core portion and towardthe interior of the second core portion such that the perimeter seam isdefined between the first outer layer and the second outer layer, andfurther wherein the perimeter edge of the first core portion is bondedto the perimeter edge of the second core portion, and even furtherwherein the first and second core portions define a unitary structureformed entirely of expanded polypropylene; wherein the first coreportion includes a secondary edge disposed radially inward from saidperimeter edge of the first core portion to define an opening, andwherein the second core portion includes a secondary edge disposedradially inward from said perimeter edge of the second core portion todefine an opening, and further wherein the opening of the first coreportion and the opening of the second core portion are aligned to definean opening through the head restraint, and still further wherein atleast a region of the secondary edge of the first core portion and thesecondary edge of the second portion define a secondary seam.
 2. Thehead restraint according to claim 1, wherein the first outer layer is acover material wrapped around the secondary edge of the first coreportion and toward the interior of the first core portion, and whereinthe second outer layer is a cover material wrapped around the secondaryedge of the second core portion and toward the interior of the secondcore portion such that the secondary seam is defined between thesecondary edge of the first core portion and the secondary edge of thesecond core portion.
 3. The head restraint according to claim 1, whereina closeout is disposed within said opening of the head restraint.
 4. Thehead restraint according to claim 3, wherein the closeout is disposedbetween said secondary edge of said first core portion and saidsecondary edge of said second core portion.
 5. The head restraintaccording to claim 3, wherein the closeout is a filter material.
 6. Thehead restraint according to claim 5, wherein the filter materialincludes at least one of a mesh material, and a net material.
 7. Thehead restraint according to claim 1, further comprising: a headrestraint post extending from one or both of said first core portion andsaid second core portion.
 8. The head restraint according to claim 7,wherein the interior of one or both of said first core portion and saidsecond core portion define a cavity for receiving said post.
 9. The headrestraint according to claim 1, wherein one of the first and secondportions defines a tongue, and the other of the first and secondportions defines a groove, and wherein the tongue of the one of thefirst and second portions is received by the groove of the other one ofthe first and second portions to define the seam.
 10. The head restraintaccording to claim 1, wherein each attachment of the first core portionto the second core portion is provided without a connection member orintervening material.
 11. A method for manufacturing a head restraint,the method comprising: defining first and second core portions frompolypropylene, each of said portion including an exterior surface, aninterior and a perimeter edge between the exterior surface and theinterior; covering at least a region of said exterior surface of saidfirst core portion with a first outer layer; covering at least a regionof said exterior surface of said second core portion with a second outerlayer; directly attaching material defining at least a region of theperimeter edge of the first core portion to material defining at least aregion of the perimeter edge of the second core portion; directlyattaching an edge of the first outer layer to an edge of the secondouter layer to define a perimeter seam therebetween wrapping the firstouter layer around the perimeter edge of the first core portion towardthe interior of the first core portion; and wrapping the second outerlayer around the perimeter edge of the second core portion toward theinterior of the second core portion such that the perimeter seam isdefined between the first outer layer and the second outer layer priorto the first and second core portions becoming fully cured, depositing apost about the interior of the at least one of the core portions;aligning at least a region of the perimeter edge of the first coreportion to at least a region of the perimeter edge of the second coreportion to define the perimeter seam therebetween; and applying pressurebetween the first core portion and the second core portions to bond atleast a region of the perimeter edge of the first core portion with atleast a region of the perimeter edge of the second core portion todefine the perimeter seam therebetween whereby the first core portionand the second core portion define a unitary structure formed entirelyof polypropylene.
 12. The method according to claim 11, wherein definingthe first and second core portions from polypropylene comprises: forminga secondary edge disposed radially inward from said perimeter edge ofthe first core portion to define an opening in said first core portion;and forming a secondary edge disposed radially inward from saidperimeter edge of the second core portion to define an opening in saidsecond core portion.
 13. A head restraint, comprising: a first coreportion including an exterior surface, an interior and a perimeter edgebetween the exterior surface and the interior; a first outer layerprovided about at least a region of said exterior surface of said firstcore portion; a second core portion including an exterior surface, aninterior and a perimeter edge between the exterior surface and theinterior; and a second outer layer provided about at least a region ofsaid exterior surface of said second core portion, wherein materialdefining at least a region of the perimeter edge of the first coreportion is directly attached to material defining at least a region ofthe perimeter edge of the second core portion, wherein an edge of thefirst outer layer is directly attached to an edge of the second outerlayer to define a perimeter seam therebetween, wherein the first outerlayer is a cover wrapped around the perimeter edge of the first coreportion and toward the interior of the first core portion, and whereinthe second outer layer is a cover wrapped around the perimeter edge ofthe second core portion and toward the interior of the second coreportion such that the perimeter seam is defined between the first outerlayer and the second outer layer, and further wherein the perimeter edgeof the first core portion is bonded to the perimeter edge of the secondcore portion, and even further wherein the first and second coreportions define a unitary structure formed entirely of expandedpolypropylene; and a head restraint post extending from one or both ofsaid first core portion and said second core portion.
 14. The headrestraint according to claim 13, wherein the interior of one or both ofsaid first core portion and said second core portion define a cavity forreceiving said post.
 15. The head restraint according to claim 13,wherein the first core portion includes a secondary edge disposedradially inward from said perimeter edge of the first core portion todefine an opening, and wherein the second core portion includes asecondary edge disposed radially inward from said perimeter edge of thesecond core portion to define an opening, and further wherein theopening of the first core portion and the opening of the second coreportion are aligned to define an opening through the head restraint, andstill further wherein at least a region of the secondary edge of thefirst core portion and the secondary edge of the second portion define asecondary seam; and wherein the first outer layer is a cover materialwrapped around the secondary edge of the first core portion and towardthe interior of the first core portion, and wherein the second outerlayer is a cover material wrapped around the secondary edge of thesecond core portion and toward the interior of the second core portionsuch that the secondary seam is defined between the secondary edge ofthe first core portion and the secondary edge of the second coreportion.
 16. The head restraint according to claim 13, wherein the firstcore portion includes a secondary edge disposed radially inward fromsaid perimeter edge of the first core portion to define an opening, andwherein the second core portion includes a secondary edge disposedradially inward from said perimeter edge of the second core portion todefine an opening, and further wherein the opening of the first coreportion and the opening of the second core portion are aligned to definean opening through the head restraint, and still further wherein atleast a region of the secondary edge of the first core portion and thesecondary edge of the second portion define a secondary seam; andwherein a closeout is disposed within said opening of the headrestraint.
 17. The head restraint according to claim 16, wherein thecloseout is disposed between said secondary edge of said first coreportion and said secondary edge of said second core portion.
 18. Thehead restraint according to claim 16, wherein the closeout is a filtermaterial.
 19. The head restraint according to claim 18, wherein thefilter material includes at least one of a mesh material, and a netmaterial.
 20. The head restraint according to claim 13, wherein one ofthe first and second portions defines a tongue, and the other of thefirst and second portions defines a groove, and wherein the tongue ofthe one of the first and second portions is received by the groove ofthe other one of the first and second portions to define the seam. 21.The head restraint according to claim 13, wherein each attachment of thefirst core portion to the second core portion is provided without aconnection member or intervening material.